Why are these energy systems important to know about?
It is helpful to have a general understanding of the energy system the body uses for aerobic exercise compared with anaerobic exercise. Each energy system provides ATP through a different chemical pathway depending on what activity we need to accomplish. When creating a workout program, it is important to recognize this so your exercise plan can be designed appropriately. Recall the principle of specificity discussed in the “Principles of Training” section. If you want to get better at a particular exercise or physical activity, you want to practice the correct energy system that the body uses to perform that exercise/ activity.
Awareness of the energy systems also helps exercisers understand why they might feel a certain way, for example, like being out of breath after a burst of high intensity exercise. If it was an exercise they were trying to sustain, then they may need to slow their pace a bit to utilize the aerobic energy system. If someone is lifting a heavy object or performing intervals with sprints, they will not be able to maintain such high intensity for more than a few seconds. Hence why we feel out of breath after intense exercise as our body is trying to regain a balanced state of oxygen intake (and blow off CO2 produced during anaerobic processes).
Anaerobic metabolism produces chemical bi-products that contribute to fatigue and the “burn” that exercisers often feel during an intense exercise. It is sort of like a signal that we will need oxygen soon. Oxygen is involved in part of a chemical process that helps remove these bi-products. Thus oxidative metabolism (using the aerobic pathway) increases during recovery after a bout of anaerobic exercise. This is why a proper recovery period to “catch your breath” is important before attempting another high intensity lift, sprint, or other short explosive interval.
Why would you want to work at such a high intensity, take a break to recover, then repeat it again, maybe even several more times?? There is really neat thing that happens to our metabolism when we are done with intense exercise like this. There is a longer recovery process that takes place and a physiological event that occurs during this time called EPOC or excess post-exercise oxygen consumption. This phenomenon describes the extra oxygen demand needed after intense exercise and explains why metabolism remains elevated as the body works toward returning to a fully recovered state. Metabolism remains elevated even though your workout is done!
